Internal-combustion engine



L.'ATWO0D.

INTERNAL yCoII/IusTIoN ENGINE.

APPLICATION FILED FEB. 24. 1921. l

Patented June 6, 1922.

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lTED lSTATES PATENT vori-"i 'ji E.

LEONARD ATWOOD, 0F BOSTON, MASSACHUSETTS.

INTERNAL-COMBUSTION ENGINE.

Application led February 24, 1921. Serial No. 447,496.

To (ZN 107mm. if may conce/n Be it known that I. LEoNARn A'rwooo, a citizen of the United States, and a resident of Boston, in the county of `Suffolk and Commonwealth of l\'[assachusetts, have invented certain new and useful Improvc ments in Internal-Combustion Engines. of which the following is a full, clear, and exact specification.

This invention relates to the type of engine set forth in my companion applications filed August 27, 1920. and Numbered 406,329 and 406,330, wherein the packing rings are inlaid in the wall of the combustion chamber instead of in the periphery of the piston, and are located at the lower end of the chamber. Since the piston head must `descend below the packing rings in order to permit the exhaust to escape` the rings will spring out into injuriousengagement with the piston when it ascends, unless means are provided for preventing it.

For such prevention, I have devised two somewhat different means, one consisting in providing the head of the piston with an annulus rising therefrom externally continuous with the periphery of the piston, but perforated close above the piston-head to permit the escape of the exhaust. The other consists in vertically grooving the upper part of the pistons periphery to reach theI exhaust ports, while keeping the piston head just above the rings.

I further improve the engine by perforating the lower end of its piston in order that thelubricating oil in the crank case and which will be splashed against the pistonfs interior at its down stroke, will pass through to and lubricate the pistons exterior surface.

In the drawings forming part of this specification, Fig. 1 is a central vertical section of an engine embodying my improvements. Fig. 2 is a perspective view of its piston. Fig. 3 is a horizontal section of the piston extension. Fig. (1 is a perspective view of another form of the piston.

The reference numeral 1 designates the piston of the engine; 2, the explosion chamer; 3, the lower section of. the cylinder: 4. a jacket sur-rounding the explosion or combustion chamber 2, and 5. the crank case. The combustion chamber is spaced at its lower end from the upper end of the lower section 3, thereby forming an annular chani nel for the exhaust, the latter escaping therefrom through a suitable conduit 6,

To the 'lower end of the combustion chamber 2 1s secured an annulus 7 for holding 1n place a set of packing rings 9 adapted to press inward against the periphery of the piston 1 and thereby prevent the escape of the charge past the latter.

So long as the head 9 of the piston is above these packing rings, the latter are all right, but after the head has descended below the rings to deliver the exhaust to the pipe 6, and rises again into engagement with the packing rings, then there is liable to be trouble; for, since the rings will have sprung inward as soon as the' piston descended below them the edge of the piston will strike the rings. If. now, the edge of the piston were tapered off in order force the rings back in again, the latter would be subjected to an amount of wear, both from the engagement with the piston and from their shunting back and forth in their seats and in contact with each,f other, that would rapidly render th'em incapable of performing their designed function. y

What I have done, therefore, has been to provide a means for preventing any such centripetal movement of the packing rings when the piston descends below them. My preferred means consists of a flange 10 rising fromthe upper end of the piston and having its outer diameter the same. as that of the piston, the height of this flange being sufficient to rise ljust above the packing rings. or even a trifle below the upper side of the top-most ring.

Through this flange 10 are several holes 11 located therein to be on a level with the exhaust annular channel 8 when the piston is at its lowest point. Thus arranged. the exhaust can pass freely through these openings 11 to the channel 8 and thence to the pipe 6, and still the packing rings are retained exactly as they are when the piston itself is contacting with them.

To reduce the compression chamber when the piston is at its upper extreme. the head 12- of the combustion chamber is centrally depressed, as at 13. leaving a restricted annular space 14 for the reception of the flange 10.

In the form of piston illustrated in Fig. 4. the piston itself is elongated and grooves 15 are longitudinally cut in the upper surface of the same down to a depth which will provide ample communication with the channel 8 when the piston is at its lowest limit,

0f course, in this form of the piston the cylinder head 12 is not centrally depressed.

A further improvement in the piston is the provision of a series of holes 1G radially through it near its lower end, so that when the piston sinks to its lower limit, the lubricatin oil deposited in the crank case 5 will be sp ashed therefrom by the action of the crank, up against the interior of the piston and will largely pass therefrom through the holes 16 into contact with the interior of the cylinder section 3 and thereby will lubricate the same and the exterior of the piston. Any excess of the oil will be removed from the exterior of the piston by a wiping ring 17 kept in place by an annul us 19.

rIhere is no need for lubrication in the combustion chamber 2 for the reason that it is larger in diameter than the piston and consequently there is no friction between the same.

Additional lubrication for the piston in the lower section of the cylinder may be provided, as from a reservoir 2O connected by a pipe 21 to the section 3, but ordinarily the oil delivered through the perforations 16 is sufficient.

In this form of engine, the fuel oil is designed to be delivered through a. pipe 22 and thence between the vpacking rings 9 intoi contact with the surface of the piston as the latter rises, so that by the time the piston reaches the upper extremity of its stroke, this oil has been entirely vaiorized by the heat and is then ignited by the compression. rIhe air for admixture with the vapor is supplied through av pipe 23, serving also to aid in the expulsion of the exhaust; all as set forth more fully in my companion application Serial No. 406,330, iiled August 27, 1920.

`What I claim is:

1. An engine comprising a cylinder provided with packing rings intermediate of its length, anda piston reciprocative therein, the exhaust port of the cylinder being close beneath said rings, and the piston being provided with means for retaining said rings in place within the cylinder when the piston is at its lower limit and uncovering said exhaust port. l

2. An engine comprising a cylinder pro-` vided with centripetally pressing packing rings intermediate of its length, an annular exhaust channel close beneath said rings for permitting the escape of the exhaust, and a piston movable in said cylinder, the piston having apertures communicating both with the space immediately above the top of the piston and with said exhaust channel when the piston is at its lowest limit, and means for holding the packing rings from springing inwardly when said piston is at said limit.

3. An engine comprising a cylinder provided with inwardly pressing packing rings intermediate of its length, an annular channel close beneath said rings for the discharge cf the exhaust, and a piston movable in said cylinder having a closed head at its upper end, and an apertured flange rising from said head, the apertures permitting access to said channel and the iiange retaining said rings from springing inwardly.

4. An engine comprising a cylinder provided with inwardly pressing packing rings intermediate of its length, and an exhaust port close beneath said rings, and a piston having a. closed head reciprocative in the cylinder, the piston having a.`flange rising from said head of the same diameter as the exterior of the piston and adapted to remain in contact with said ringsv when the piston is at its lowest limit and the piston head is below the level of said exhaust port, said flange having an opening through it to communicate with said port at the same time.

5. An internal combustion engine comprising a cylinder provided with inwardly pressing packing rings intermediate of'its length and an annular exhaust channel close beneath said lrings, and a. piston having a. closed head movable in said cylinder, the piston having a fiange rising from said head equal in exterior diameter to that of the piston, and the fiange having a plurality of radial openings through it close above said head.

In testimony that I claim the foregoing invention, I have. hereunto set my hand this 7th day of February, 1921.

. LEONARD lATWOOD. 

